108 



MUSIC. 



The ninth is a discord, which is usually accom- 

 panied with the third mid fifth. This is expressed in 

 No. 1, and in a composition of four parts, it is 

 expressed as in No. 2 ; yet, as in No. 3, it is fre- 

 quently accompanied with a fourth and fifth, but in 

 compositions of three parts the fifth is left out. 



We will here exemplify what is termed the har- 

 mony of the scale, or the accompanying tones which 

 produce harmony, with all the notes of an octave. 



Harmony of the scale, ascending. 



a 



*= 



Harmony of the scale, descending. 



What we have now been considering may be 

 regarded as an elementary view of the first principles 

 of thorough or fundamental bass. The following is 

 a synoptical view of the chords employed in the 

 fundamental bass : 



The arrangement and disposition of musical sounds 

 into Airs, Songs, Overtures, Sonatas, &c., is denomi- 

 nated composition. If two parts of a piece, such as 

 the air and bass, both ascend or descend, or remain 

 at the same pitch during one measure, these parts are 

 said to have a similar motion. When one part either 



ascends or descends while the other remains at the 

 same pitch, the parts are said to go by oblique mo- 

 tion. But the parts are said to go by contrary motion, 

 when one of them ascends while the other descends. 

 The motion is said to be by degrees, when the inter- 

 val between any tone and that next succeeding it, is 



